Laboratory of Immunology, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Bethesda, Maryland 20892, USA.
Invest Ophthalmol Vis Sci. 2013 Jun 10;54(6):4017-25. doi: 10.1167/iovs.13-11937.
MicroRNA-155 (miR-155) and STAT3 are implicated in uveitis and pathogenic mechanisms of CNS autoimmune diseases. In our study, we used miR-155(-/-) mice and mice with targeted STAT3 deletion in T cells (CD4-STAT3KO) to investigate roles of miR-155 and STAT3 in the development of experimental autoimmune uveitis (EAU), a mouse model of human uveitis.
We induced EAU in WT, miR-155(-/-), or CD4-STAT3KO mice by immunization with interphotoreceptor retinoid-binding protein/complete Freund's adjuvant (IRBP/CFA) or adoptive transfer of T cells. EAU was assessed by funduscopy and histology. RNA expression was analyzed by quantitative PCR (qPCR), while cytokine production was assessed by fluorescence-activated cell sorting (FACS).
We used a combination of genomic and genetic tools to provide the first evidence that STAT3 binds directly to the miR-155 locus and that STAT3 is required for miR-155 expression. Furthermore, STAT3-dependent increase in miR-155 expression in vivo correlated temporally with onset of EAU, and miR-155(-/-) or CD4-STAT3KO mice did not suffer EAU. CD4(+) lymph node cells from IRBP-immunized WT mice transferred EAU to naïve wild-type (WT) and miR-155(-/-) mice, while miR-155(-/-) IRBP-specific T cells did not.
Although miR-155 and STAT3 have been implicated in the etiology of multiple sclerosis (MS), uveitis, or rheumatoid arthritis, their exact roles in these diseases are unclear. We show here for the first time to our knowledge that STAT3 regulates miR-155 expression in Th17 cells. We show further that STAT3 and miR-155 form an axis that promotes the expansion of pathogenic Th17 cells that mediate uveitis. Thus, STAT3 and miR-155 may be therapeutic targets for treating uveitis and other Th17-mediated inflammatory disorders.
microRNA-155（miR-155）和 STAT3 参与葡萄膜炎和中枢神经系统自身免疫性疾病的发病机制。在本研究中，我们使用 miR-155（-/-）小鼠和 T 细胞中靶向 STAT3 缺失的小鼠（CD4-STAT3KO）来研究 miR-155 和 STAT3 在实验性自身免疫性葡萄膜炎（EAU）中的作用，EAU 是人类葡萄膜炎的小鼠模型。
我们通过用 interphotoreceptor retinoid-binding protein/complete Freund's adjuvant（IRBP/CFA）免疫或过继转移 T 细胞在 WT、miR-155（-/-）或 CD4-STAT3KO 小鼠中诱导 EAU。通过眼底镜和组织学评估 EAU。通过定量 PCR（qPCR）分析 RNA 表达，通过荧光激活细胞分选（FACS）评估细胞因子产生。
我们使用基因组和遗传工具的组合提供了第一个证据，证明 STAT3 直接与 miR-155 基因座结合，并且 STAT3 是 miR-155 表达所必需的。此外，体内 STAT3 依赖性 miR-155 表达增加与 EAU 的发作时间相关，并且 miR-155（-/-）或 CD4-STAT3KO 小鼠不会发生 EAU。从 IRBP 免疫的 WT 小鼠的 CD4（+）淋巴结细胞将 EAU 转移给幼稚的野生型（WT）和 miR-155（-/-）小鼠，而 miR-155（-/-）IRBP 特异性 T 细胞则不会。
尽管 miR-155 和 STAT3 已被牵连到多发性硬化症（MS）、葡萄膜炎或类风湿性关节炎的病因中，但它们在这些疾病中的确切作用尚不清楚。我们在这里首次证明，据我们所知，STAT3 调节 Th17 细胞中的 miR-155 表达。我们进一步表明，STAT3 和 miR-155 形成一个轴，促进介导葡萄膜炎的致病性 Th17 细胞的扩增。因此，STAT3 和 miR-155 可能是治疗葡萄膜炎和其他 Th17 介导的炎症性疾病的治疗靶点。
